Department of Medical Genetics, University of Wisconsin, Madison, WI, 53706, USA.
Mamm Genome. 2013 Oct;24(9-10):349-57. doi: 10.1007/s00335-013-9468-9. Epub 2013 Aug 9.
Mutations in the gene for destrin (Dstn), an actin depolymerizing factor, lead to corneal abnormalities in mice. A null mutation in Dstn, termed Dstn (corn1) , isolated and maintained in the A.BY background (A.BY Dstn (corn1) ), results in corneal epithelial hyperproliferation, inflammation, and neovascularization. We previously reported that neovascularization in the cornea of Dstn (corn1) mice on the C57BL/6 background (B6.A.BY-Dstn (corn1) ) is significantly reduced when compared to A.BY Dstn (corn1) mice, suggesting the existence of genetic modifier(s). The purpose of this study is to identify the genetic basis of the difference in corneal neovascularization between A.BY Dstn (corn1) and B6.A.BY-Dstn (corn1) mice. We generated N2 mice for a whole-genome scan by backcrossing F1 progeny (A.BY Dstn (corn1) × B6.A.BY-Dstn (corn1) ) to B6.A.BY-Dstn (corn1) mice. N2 progeny were quantitatively phenotyped for the extent of corneal neovascularization and genotyped for markers across the mouse genome. We identified significant association of variability in corneal neovascularization with a locus on chromosome 3 (Chr3). The validity of the identified quantitative trait locus (QTL) was tested using B6 consomic mice carrying Chr3 from A/J mice. Dstn (corn1) mice from F1 and F2 intercrosses (B6.A.BY-Dstn (corn1) × C57BL/6J-Chr3(A/J)/NaJ) were phenotyped for the extent of corneal neovascularization. This analysis showed that mice carrying the A/J allele at the QTL show significantly increased neovascularization. Our results indicate the existence of a modifier that genetically interacts with the Dstn gene. This modifier demonstrates allelic differences between C57BL6 and A.BY or A/J. The modifier is sufficient to increase neovascularization in Dstn (corn1) mice.
肌动蛋白解聚因子 destrin（Dstn）基因突变可导致小鼠角膜异常。在 A.BY 背景下分离并维持的 Dstn 缺失突变（Dstn（corn1））导致角膜上皮过度增殖、炎症和新生血管形成。我们之前报道过，与 A.BY Dstn（corn1）小鼠相比，C57BL/6 背景下 Dstn（corn1）小鼠的角膜新生血管化显著减少（B6.A.BY-Dstn（corn1）），这表明存在遗传修饰因子。本研究的目的是确定 A.BY Dstn（corn1）和 B6.A.BY-Dstn（corn1）小鼠角膜新生血管化差异的遗传基础。我们通过将 F1 后代（A.BY Dstn（corn1）×B6.A.BY-Dstn（corn1））回交至 B6.A.BY-Dstn（corn1）小鼠，生成了用于全基因组扫描的 N2 小鼠。N2 后代的角膜新生血管化程度进行定量表型分析，并对跨越小鼠基因组的标记进行基因分型。我们确定了角膜新生血管化的变异性与 3 号染色体（Chr3）上的一个位点显著相关。使用携带 A/J 小鼠 Chr3 的 B6 同系小鼠对鉴定的数量性状基因座（QTL）的有效性进行了测试。来自 F1 和 F2 杂交（B6.A.BY-Dstn（corn1）×C57BL/6J-Chr3（A/J）/NaJ）的 F1 和 F2 杂交后代的 Dstn（corn1）小鼠对角膜新生血管化的程度进行了表型分析。该分析表明，携带 QTL 上 A/J 等位基因的小鼠表现出明显增加的新生血管化。我们的结果表明存在一种修饰因子，它与 Dstn 基因发生遗传相互作用。该修饰因子在 C57BL6 和 A.BY 或 A/J 之间表现出等位基因差异。修饰因子足以增加 Dstn（corn1）小鼠的新生血管化。
